Two identical small metal spheres 3 cm apart

1. The problem statement, all variables and given/known data
Two identical small metal spheres 3 cm apart attract each other with a force of 150N electrical module. They are temporarily connected by a conducting wire, which is then removed, making both charges equal.

a) Determine the initial electrical charges if they now repel each other with a force of 10N module.(It is assumed that the charge of each sphere is uniformly distributed)

b) From a graphical analysis, show that if the repulsive electric force initial situation is unrealistic.

2. Relevant equations
Coulombs law

3. The attempt at a solution
Too much to copy, this is what i have... its french, I try to translate it as much as possible